Ceramic capacitors are well known in the art. Multilayer ceramic capacitors (“MLCC”) are frequently used as surface mounted devices (“SMD”) because of their high package density. Typically, ceramic capacitors are manufactured by assembling a stack of green compact plates and conducting metal layers alternatingly, followed by sintering the stack to a compact sintered body. A first set of metal layers are electrically contacted by a first end terminal covering one side wall of the sintered body, and a second set of the metal layers are electrically contacted by a second end terminal covering another side wall, for instance, a side wall opposing the first side wall. The end terminals are intended as electrodes having different electrical polarities. The metal layers are arranged in an interdigital structure so that a metal layer contacting the first end terminal is facing a metal layer contacting the second end terminal, the metal layers being spaced apart by the dielectric ceramic plates. The metal layers spaced apart by the ceramic plates form an active zone of the capacitor with a well-defined capacitance.
However, capacitors made of ceramics are prone to cracks caused by mechanical shocks, and thermal shocks as well, which may destroy the device or alter the electrical properties of the capacitor. Often, cracks emerge at the outer surfaces and propagate to the active zone of the device. Thermal shock cracks and cracks due to flexing of a printed circuit board (“PCB”) to which the capacitor is mounted are two of the extrinsic defects commonly occurring in multilayer ceramic capacitors. In addition, mechanically induced multiple cracks may occur in multilayer ceramic capacitors. These types of cracks have the same defect mechanisms in common. Firstly, mechanical stresses or forces are coupling through the ductile metal layers, and secondly, cracks occur in the underneath brittle ceramic capacitor layers. When these cracks propagate and cut through the active zone of the capacitor they may lead to electrical failures of the device.
In U.S. Pat. No. 8,576,537 a ceramic capacitor is described, where crack mitigation void patterns are provided close to the surface of the ceramic body. The crack mitigation void pattern is intended to channel emerging cracks, which originate from the surface and propagate into the ceramics body in a safe zone outside the active capacitor zone inside the ceramic body.
The present invention is directed toward overcoming one or more of the above-mentioned problems.